Hammer-drill.



W. PRELLWITZ.

HAMMER DRILL, APPLICATION FILED FEB. 6, 1909.V

Patented Nov. 18, 1913.

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' WILLIAM rinirmwrrz, or nasfi PENNSYLVANIA, Assroiioaro rivonrtsoign-'nann l t COMPANY, or NEW YORK, 1v. Y., a oonronarrou orivnw :mRs'EY.'

intresse.

y To all eti/7mm it may concern.'

, a citizen of the United States, and resident- Hartman-DRILL.

` Be it known that I, VViLLIAM PRELLwrrz',

of Easton, in the county of Northampton and'State of Pennsylvania, have invented a new and useful Improvement in Hammer- Drills, of which the following is a specification. i Y

This invention rela-tes to hammer drills and has for its object to provide a novel construction at the front lend of the drill, which construction, combined with a hollow drill steel of novel form, will be particularly well adapted for feeding fluid under pres,- sure to the drill steel; fluidtight packings being provided for the pressure fluid feeding chamber, the said chamber and its adjacent parts being located within the front head of cui@ aan.

[In the accompanying drawings, Figure 1 represents in side elevation the front end of a'hammerdrill, with the invention applied thereto, the hollow drill steel being broken away, Fig. 2 is a front end view of the same,

Fig. 3 is a detail longitudinal central section through the front end of the hammer drill with its steel'and anvil block shown in vside elevation, and Fig. 4 is a transverse section taken in the plane of the line A-A of Figa, looking in the direction of the arrows, the drill steel being removed.

The drill cylinder is denoted by 1 and its hollow front head by 2, which front head is held in position by longitudinally extended tie bolts 3. `A drill steel receiving chuck 4 is mounted within the cylinder 1 and is provided with an open ended socket 5 angular in cross section to correspond to the striking end of the drill steel. This chuck is interllocked by wings LF, 4l* with the front end of a sleeve 6 also mounted withinthe This sleeve 6 is rotated in the usual manner by the reciprocation of the hammer piston, not shown herein, and provided with an annular interior rib 7 forming a reduced bore for receiving the shank 8 of an anvil block, the head 9 of which block is located in position to engage the striking end of a hollow drill steel 10 which projects beyond the inner end of the chuck 4. 4The drill steel is provided adjacent to its angular' striking end with a cylindrical portion 11. A short tube 12 is mounted within the hollow front head 2 and is spaced from the cylindrical portion 11 of Specieaton of Letters Patent. 'Ent@d`N0w,1Ss 19135. applicationfnearebruarye,1909.. seriaiirolavasuo. A` H l l the drill steel to form an annular-pressure fluid feeding chamber 13. Thisv tube 12 is further provided with a circumferential .groove 14- which forms an outer pressureA fluidv feeding chamber, which chamber is in open communication with the 'inner chamber 1?l through one or lmore transverse holes 15. A fluid.` pressure supply pipe 16 1s engaged. with a transverse hole 17 in the hollow front head 2 opposite thelouter chamber 14 for bringing the inner chamber 13 into open communication with vthe pressure fluid supply. The longitudinally arranged yaxial bore 18 of the hollow drillv steel 10'.

is provided with a transverse hole 19 openL ing into the chamber 13. A rigid ring 20 is interposed between an interior annular shoulder 21 on the hollow front head 2 and the outer ends of the cylinder, chuck and rotating: sleeve. An elastic washer 22 and the Vbase 23 ofv a cup washer 24 is interposed be ,tween the ring 20 and the inner end of the tube 12. An elastic ring 25 and the base 26 of a cup washer 27 are interposed between the end of the front head 2 and the outer end of the tube 12. These cup washers 2l, 27, form fluid tight packings between the cylindrical l portion 11 of the drill steel and the tube 12 for preventing the escape of the pressure fluid from the chamber 13. The elastic washers 22 and' serve as fluid tight packings for preventing the leakage of the pressure fluid from the outer chamber 14.

It will be seen that by the-construction and arrangement of the parts as here shown. and described,V a fluid tight packing is provided which will prevent the escape of the pressure fluid being fed to the drill steel an'd at the same time ready access may beobtained for the renewal of th e several parts. Furthermore, the parts are so arranged ,that `the slight longitudinal reciproeatory movements of the drill steel and its rotation during the operation of the drill, will not interfere with the feed of the pressure fluid to the drill steel.

That I claim is Y l. In combination, a cylinder, a chuck, a hollow front head, a hollow drill steel having a cylindrical port-ion at the outer end of the chuck, a tube within theV front head spaced from said cylindrical portion of the drill steel to form a pressure `fluid feeding chamber, means for feeding pressure fluid passage connecting its. bore 'with said chamber, the said tube having a circumferential groove in open communication with the pressure fluidl feeding means and with the said pressure fluid feeding chamber, cup washers interposed between the ends of the said tube and the cylindrical portion of the drill steel to form fluid 'tight packings'for the pressure duid feeding chamber, and elastic rings interposed between the outer and inner ends of said tube and the front head and outer end of the cylinder, respectively.

2. In combination, a cylinder, a .chuck rotatably mounted therein, a hollow .front head, a hollow drill steel having a cylindrical portion at the outer end of the chuck, a tube within the front head spaced from said cylindrical portion of the drill steel to form a pressure fluid feeding chamber, means for feeding pressure fluid to said chamber, said drill steel having a passage connecting its bore 'with said chamber, the.

said tube having a circumferential groove in ressure Huid feeding chamber, cup washers interposed between the ends of the said tube and the cylindrical portion of the drill steel to form Huid tight packingsfor the pressure fiuid feeding chamber, and elastic "rings inter= posed' between the outer and inner ends of said tube and the front head and outer end of the cylinder, respectively.

In testimony7 that I claim the foregoing as my invention vI have signed my name in presence of two witnesses, ofFebruary 1909.

WILLIAM PRELLWITZ.

Witnesses:

F. GEORGE BARRY, HENRY THEME.

c this fourth dayA y 

